The washing machine conducts washing, rinsing and spinning processes for removal of dirt stuck to clothes by means of action of detergent and water. In the washing machines, there are drum type, agitator type and pulsator type washing machines.
The drum type washing machine carries out washing by introducing washing water, the detergent and the laundry into an inside of a drum having a plurality of tumbling ribs on an inside surface of the drum, and rotating the drum around a horizontal shaft slowly, to lift/drop the laundry with the tumbling ribs that gives impact to the laundry to wash the laundry. Though the drum type washing machine has advantages in that it gives almost no damage to the laundry and has a small water consumption, the drum type washing machine has disadvantages in that it has a low washing capability to required heating of the washing water for enhancing the low washing capability, with consequential large power consumption, requires a long time for washing, and has much noise.
The agitator type washing machine, carrying out washing by rotating a washing rod projected upward from a central part of the washing tub in left/right directions, has disadvantages in that it has great noise and vibration and damages laundry, though it has an excellent washing capability. In general, such an agitator type is suitable for a large sized washing machine.
The pulsator type carries out washing with friction between water circulation caused by a disk like pulsator on a bottom of a washing tub and the laundry. The greatest advantages of the pulsator type washing machine are short washing time period and large capacity washing machine can be fabricated, and the pulsator type washing machine has relatively low noise and vibration, and costs low. Though the pulsator type washing machine has disadvantages in that it has entangling of laundry, and gives relatively much damage to the laundry, the pulsator type washing machines are spread wider gradually as above problems are corrected and performance is improved recently owing to technical improvements, such as elimination of the clutch, employing a direct driving type, and the like.
A system of a general washing machine, particularly to the pulsator type washing machine will be explained. An outside of the washing machine is a cabinet. The cabinet has a water storage tub supported on a supporter in an inside thereof. Washing water is filled inside of the water storage tub.
There is an open/closable cover on top of the cabinet. There is a drain opening passed through one side of the water storage tub, to which a drain hose is connected for draining washing water from the water storage tub to an outside of the washing machine.
There is a washing tub rotatably mounted in the water storage tub. The washing tub has a plurality of pass through holes for communication with the water storage tub. Washing is carried out in the washing tub, actually. The pulsator is mounted on a bottom of the washing tub, for rotation together with, or independent from the washing tub.
The rotation of the washing tub and the pulsator is carried out by a motor mounted under the water storage tub. The motor is provided with a rotor for selective rotation of the washing tub and the pulsator, and a stator for making the rotor to rotate by magnetic reaction with the rotor.
In the meantime, for adding various functions to and improving performance of the washing machine, a sensor may be fitted for sensing information (for an example, a temperature) on an inside of the washing tub. A general structure of the sensor fitted to the water storage tub is illustrated in FIG. 1. Referring to FIG. 1, there is a pass through hole 1a in the water storage tub 1, through which a fore end of a sensor 2 is exposed to an inside of the water storage tub 1. For firm fixation of the sensor 2, the sensor 2 has a mounting plate 4 fastened to a fastening boss 3 by fastening screws 5. For prevention of washing water leakage through the pass through hole 1a for the sensor 2, there is a sealing material 3a applied between the mounting plate 4 and the water storage tub 1.
However, the washing machine with the foregoing sensor 2 mounting structure has the following problems.
First, the making of the pass through hole 1a in the water storage tub 1 for fitting the sensor requires application of the sealing material 3a for prevention of water leakage through the pass through hole. Moreover, the leakage may cause short circuit or electric shock since the sensor 2 is in general operative on electricity.
Second, the washing machine with the sensor 2 fitted thereto is a high class product with relatively many functions and improved function, but with not so many kinds and demands. Accordingly, there is a problem that separate design and fabrication is required for the water storage tub 1 with the pass through hole 1a, even if there is not so many kinds and demands of the washing machine.